66201973918866 has 64 divisors (see below), whose sum is σ = 148935347827200. Its totient is φ = 22066789817520.

The previous prime is 66201973918819. The next prime is 66201973918867. The reversal of 66201973918866 is 66881937910266.

It is a junction number, because it is equal to n+sod(n) for n = 66201973918794 and 66201973918803.

It is not an unprimeable number, because it can be changed into a prime (66201973918867) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207084775 + ... + 207404213.

It is an arithmetic number, because the mean of its divisors is an integer number (2327114809800).

Almost surely, 2^{66201973918866} is an apocalyptic number.

66201973918866 is an abundant number, since it is smaller than the sum of its proper divisors (82733373908334).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66201973918866 is an equidigital number, since it uses as much as digits as its factorization.

66201973918866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366843 (or 366825 counting only the distinct ones).

The product of its (nonzero) digits is 282175488, while the sum is 72.

The spelling of 66201973918866 in words is "sixty-six trillion, two hundred one billion, nine hundred seventy-three million, nine hundred eighteen thousand, eight hundred sixty-six".